Food processors of the type to which the present invention is applicable have a working bowl with a motor-driven shaft projecting upwards in the bowl on which various selected rotary food processing tools can be engaged to be driven by the shaft for performing various food processing operations in accordance with the desires of the user. A detachable cover is secured over the top of the bowl during use. The cover includes a feed tube having a mouth that opens downwardly through the cover into the top of the bowl. The food items to be processed are placed in this feed tube and are then manually pushed down through the feed tube into the bowl by means of a removable food pusher which is adapted to slide down in the manner of a plunger through the feed tube. Further information with respect to such food processors may be obtained by reference to U.S. Pat. Nos. 3,892,365--Verdun, 3,985,304--Sontheimer and 4,127,342--Marcel Coggiola.
The rotary tools used in food processors are driven by relatively powerful motor drive arrangements and have the capability of causing injury to a finger or hand if the user could inadvertently bring a hand into contact with the motor-driven tool. For this reason, a bowl cover safety feature is conventionally incorporated into these units. This feature requires that the cover be firmly locked onto the bowl in normal operating position before the motor will start. This requirement is achieved by making the cover, which locks rotationally to the bowl, with a projection or member which causes the closing of a switch carried by a housing only when the cover is properly locked in its normal operating position on the bowl. Depending upon the type of food processor the aforesaid projection may actuate the switch directly or through an intermediate linkage. Thus, the motor cannot be energized before the cover is properly positioned on the bowl. However, this requirement that the cover be locked in place would not prevent injury if a hand were inserted down through the feed tube. Accordingly, the feed tube in accordance with another safety feature is deliberately designed in terms of shape, cross-section and height, i.e. it is relatively tall and narrow, to make it impossible for an adult inadvertently to insert a hand sufficiently far down into the feed tube to touch a rotating tool located in the upper portion of the working bowl. In addition, a food pusher is provided insertable into the feed tube for feeding food items down into engagement with the food processing tool.
The above limitations imposed on the size and shape of the feed tube for safety considerations limits the size and shape of food items which can be inserted and food processing operations which can be performed on such food items. For example, lengthwise slicing of carrots, cucumbers, celery, etc. could of necessity be severely limited to the crosswise dimension of the narrow prior art feed tube.